Stress and Fetal Development Flashcards
What is Barker’s Hypothesis?
‘-Coronary heart disease, Type 2 diabetes, stroke and hypertension originate in developmental plasticity, in response to undernutrition during fetal life’
-stress during sensitive periods in fetal development may explain the origin of adult diseases
What is the Programming Hypothesis?
-non-genetic factors can organize or imprint permanently on physiological systems
-maternal stress can directly affect the structure and function of biological systems.
-expansion of Barker’s theory
What is the detailed explanation [graph] of the programming hypothesis?
-Fetal growth is affected by fetal hormonal/nutritional milieu, genetic factors, and other maternal factors
-Issues in “programming” can lead to:
–birth injuries, defects, disabilities
–changes in organ function, and metabolism
-which affects adult health (with SES and health behaviours contributing)
How is the HPA axis affected during pregancy?
-estrogen stimulates cortisol production
-increases during pregnancy
-increased cortisol is bound
-ACTH secretion increases
-cortisol production increases
What is the role of Glucocorticoid in fetal development?
-influence growth in uterus, activity of pancreas, HPA axis & cardiovascular activity
-maturation of organ system
-end of pregnancy, increased in level of glucocorticoid (trigger of mechanism that leads to birth)
-postnatal survival & postnatal adaptation
-accelerate lung maturation, decreases respiratory distress syndrome in premature infants
Why are moderate levels of stress essential for optimal development?
-sensitizes developing nervous system
-develop adaptive response to stress
-rats: benefits later learning
What is the physiological impact of maternal stress?
-increased infant mortality and preterm births
-lower birth weight and head circumference
-foetal movement & heart rate [babies should be moving a lot in the womb, if they don’t its because of stress]
-HPA axis response
-brain structure
What are the long-term psychological effects?
-deficits learning and memory
-temperament (calm or fussy)
-ADHD (still need genetic risk)
-Schizophrenia (still need genetic risk)
-regulation of behaviour and emotion
What contributes to chronic stress, and what are the consequences?
-trait anxiety, state anxiety, and daily hassles
-linked to delayed language development
-lower intellectual functioning
What are the characteristics of Pregnancy Specific Anxiety (PSA)?
-stressors related to pregnancy
-shorter gestation
-decreased mental and motor development
-disruptive temperament, attention regulation problems & higher levels of restlessness
-Maternal stress in the womb can predict drug addiction in adulthood
What are the characteristics of the critical period/period of susceptibility?
-susceptible to damage
-environmental factors that interfere with growth during critical period can alter development of organs and systems
-differs depending on system or organ
What are some of the consequences of threats during fetal development?
-determines the developmental process affected
-teratogen in early pregnancy may result in major structural malformation [may lead to miscarriage]
-same teratogen later may result in neurobehavioural deficits
What does the research on the timing of stress tell us?
-research is mixed on impact on timing of stress
-mid-gestation exposure = worse outcomes
-3rd trimester exposure higher negative outcomes
-non-human: early gestation exposure more detrimental than mid-gestation
-cumulative stress throughout pregnancy vs. 1 particular period?
Which is the most serious trimester in terms of stress on the fetal development?
-they are all critical.
-could be first and second, but its bad in all trimesters [trick question]
How did the Montreal Ice Storm of 1998 affect fetal development?
-maternal stress & cognitive development
-141 women in various trimesters
-they did the Bayley IQ test on babies when born
-results: if the mother had high stress during the first or second trimester, the baby was born with a lower IQ; no impact on IQ of the babies when the mothers were in the third trimester
